Pygmalion 3

How does Henry Higgins get 'some of his own back' in Acts IV and V?
When he says,"How the devil do I know what's to become of you?", he caused Eliza to feel unwanted and abandoned. He used his rough tone of voice and unpleasant words to show Eliza that he did not care for her. His exasperated and irritated tone expressed that he wanted to wash his hands off the whole affair. The

into her mouth." This is an insult to Eliza as Higgins is accusing her of being unintelligent. He also implies that she is incapable of doing anything on her own. He is also reminding her that she has no education; that everything she knows comes from him. He is trying to put her down, saying that everything was his effort and not Eliza's.
In these ways, Higgins managed to get 'some of his own back'.